Weil-McLain NX - Manual (Page 7)

WM 550-141-996/1105 Page 7
RWB 6104WMNX R1005
Inspect/Prepare Installation Site
Clearances to Burner and Appliance
Provide space around burner and appliance for
ease of service and maintenance.
Check the minimum clearances against those
shown by the appliance manufacturer and by ap-
plicable building codes.
Inspect Chimney or Direct Vent System
Inspect the chimney or vent. Make sure it is prop-
erly sized and in good working condition. Follow
the instructions supplied by the appliance manu-
facturer.
Combustion Air Supply Information
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Warning–Adequate Air
Supply Required
The burner cannot properly burn the fuel if it is
not supplied with a reliable combustion air
source. A non-reliable air source could result in
incomplete combustion, causing sooting and
possible carbon monoxide emission.
Possible Sooting &
Asphyxiation Hazard
S104
!
one near the bottom of the enclosure. Each open-
ing must have a free area of not less than one (1)
square inch per 1,000 BTU’s per hour of the total
input rating of all appliances within the enclosure.
The openings should have free access to the build-
ing interior, which should have adequate infi ltration
from the outside.
Exhaust fans and other air-using devices: Size
air openings large enough to supply all air-using
devices in addition to the minimum size required
for combustion air. If there is any possibility of the
equipment room developing a negative pressure
due to exhaust fans, clothes dryers, etc., either
pipe combustion air directly to the burner or provide
a sealed enclosure for the burner and supply it with
its own combustion air supply.
Safety Shutoff for Direct Vent System
The direct vent blocked fl ue safety shut off system,
refer to Figure 2, shuts down the burner if the ex-
haust fl ue is blocked and/or if the air inlet is blocked.
It recognizes a blocked fl ue by sensing excessive
pressure in the combustion chamber. It recognizes
a blocked inlet by sensing excessive vacuum in the
air inlet adapter.
This system meets the requirements for a blocked
fl ue or blocked combustion air inlet per CSA Stan-
dard B140.0. It is designed to interrupt the cad cell
circuit and allow the control to shut down the burn-
er.
Direct/Sidewall Venting Application
For direct vent installations, follow instructions pro-
vided with appliance and direct vent system. Out-
side combustion air is required for direct venting.
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Site Preparation
SK9803A
Figure 2. Pressure Switch Installation
See NFPA Standard 31 for complete details.
Appliances located in confi ned spaces: All
confi ned spaces should have two (2) permanent
openings; one near the top of the enclosure and